Pregnant women, health workers, children, and adults with chronic conditions should be first to roll up their sleeves to get the swine flu shot when it's ready.

That's the recommendation of the Public Health Agency of Canada, which released its priority list for flu shots today.

Dr. David Butler-Jones - Canada's chief public health officer - said those groups are most vulnerable to the H1N1 virus and should be vaccinated first.

Vaccinations are expected to start in November.

That's weeks behind the United States, which is aiming to start inoculations in October, and Europe, which expects vaccinations to start this month.

But vaccinations could begin sooner if the virus surges before the flu shots are ready and health officials are convinced the vaccine is safe.

The federal government has signed a contract with pharmaceutical giant GlaxoSmithKline to produce a new vaccine for swine flu. On Monday, the company said a single dose of swine flu vaccine is enough to protect most healthy adults from the virus.

Canada's vaccine priority list mirrors recommendations made by the World Health Organization and the U.S. government.

The World Health Organization has recommended that countries first offer vaccine to health-care workers to ensure systems are able to cope with the expected increase in demand.

It suggests if vaccine has to be rationed at first, countries should consider putting pregnant women, children and adults with chronic health conditions at the front of the line.